Re: Sending message between objects - C / C++ / MFC Discussion Boards

Re: WebSockets in native C++ (not managed)

enhzflep19-Feb-12 12:19

19-Feb-12 12:19

It's a pleasure. I thought my idea would prove unpopular, though have read RFCs and modified code to conform in the past. The value of what I learned far exceeds the value of the time taken to do it, sure beats simply downloading a working implementation.

On a side note - nice sig! I've said for a long time "Everything's easy.... You just have to know how. Building a nuclear bomb is easy - _if_ you know how"

Sending message between objects

aangerma16-Feb-12 9:16

aangerma

16-Feb-12 9:16

Hello,

I have a dialog that contains some radio buttons and a list box I wondered how can I pass a message to another object that the user chaghed his selection by press one of the redio buttons, I need to call to a method of the second object accordeing the user selction .

thanks

Re: Sending message between objects

David Crow16-Feb-12 10:54

David Crow

16-Feb-12 10:54

What is the second object?

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Re: Sending message between objects

aangerma16-Feb-12 19:42

aangerma

16-Feb-12 19:42

Object of a non dialog class

Re: Sending message between objects

Albert Holguin16-Feb-12 18:15

Albert Holguin

16-Feb-12 18:15

It depends how the objects are subclassed (or derived) and who their parent is. Just about all buttons in MFC are CWnd derived, but their event handlers are usually managed by the parent window (usually some CDialog or some sort of form).

If the second object that you're referring to is another button type of object, that is owned by the same parent window, then it's ok to make direct calls to access the other object. On the other hand, if that other object is in a separate dialog or form, then you should pass a message using SendMessage or PostMessage to the parent window and let it handle the event.

It's going to make quite a big difference as to what these "objects" you are talking about are and who the owner is. A number of different solutions will probably work, but you should be careful and follow framework guidelines as you may end up with an unstable solution.

Re: Sending message between objects

enhzflep16-Feb-12 18:19

enhzflep

16-Feb-12 18:19

Its a simple process with a number of small steps.

1. Wire-up the message handling of the radio buttons so that you get a WM_NOTIFY (or whatever the pertinent message is) whenever the active radio-button in the group changes.

2. Call method of object 2 with the selected option passed in as a variable somehow - either as text, or (preferably) as an INT that represents the choice number.

Here's a dialog-based app that demonstrates the principle. Whether you call the method of the second object when the selection changes or when an 'action' button is pressed, is up to you.

(And yes, I do realize that as they're radio-buttons, one of the options should be checked by default - just can't remember how just this minute - it was easier and quicker to add a test case to check if an option had been selected yet or not Blush | :O

)

resource.rc

XML

// Generated by ResEdit 1.5.8
// Copyright (C) 2006-2011
// http://www.resedit.net

#include <windows.h>
#include <commctrl.h>
#include <richedit.h>
#include "resource.h"




//
// Dialog resources
//
LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
DLG_MAIN DIALOGEX 6, 5, 194, 106
STYLE DS_3DLOOK | DS_CENTER | DS_SETFONT | WS_CAPTION | WS_VISIBLE | WS_GROUP | WS_THICKFRAME | WS_SYSMENU
CAPTION "Code::Blocks Template Dialog App"
FONT 8, "Tahoma", 0, 0, 1
{
    PUSHBUTTON      "&Test", IDC_BTN_TEST, 138, 5, 46, 15
    PUSHBUTTON      "&Quit", IDC_BTN_QUIT, 138, 29, 46, 15
    GROUPBOX        "Static", IDC_STATIC, 13, 16, 114, 68
    AUTORADIOBUTTON "Radio Button 1", IDC_RADIO1, 38, 32, 63, 8
    AUTORADIOBUTTON "Radio Button 2", IDC_RADIO2, 38, 45, 63, 8
    AUTORADIOBUTTON "Radio Button 3", IDC_RADIO3, 38, 59, 63, 8
}

resource.h

#ifndef IDC_STATIC
#define IDC_STATIC (-1)
#endif

#define DLG_MAIN                                101
#define IDC_BTN_TEST                            1000
#define IDC_BTN_QUIT                            1001
#define IDC_RADIO1                              1002
#define IDC_RADIO2                              1003
#define IDC_RADIO3                              1004

main.cpp

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <stdio.h>

#include "resource.h"

HINSTANCE hInst;
int curRadioOption = -1;

BOOL CALLBACK DialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    char msgBuffer[1024];
    switch(uMsg)
    {
        case WM_INITDIALOG:
            /*
             * TODO: Add code to initialize the dialog.
             */
            return TRUE;

        case WM_CLOSE:
            EndDialog(hwndDlg, 0);
            return TRUE;

        case WM_COMMAND:
            switch(LOWORD(wParam))
            {
                /*
                 * TODO: Add more control ID's, when needed.
                 */
                case IDC_BTN_QUIT:
                    EndDialog(hwndDlg, 0);
                    return TRUE;

                case IDC_BTN_TEST:
                    if (curRadioOption != -1)
                        sprintf(msgBuffer, "You clicked the \"test\" button\nCurrent radio selection: #%d", curRadioOption);
                    else
                        sprintf(msgBuffer, "No radio-button option selected...\nPlease select an option then try again");

                    MessageBox(hwndDlg, msgBuffer, "Information", MB_ICONINFORMATION);
                    return TRUE;

                case IDC_RADIO1:
                    curRadioOption = 1;
                    return true;

                case IDC_RADIO2:
                    curRadioOption = 2;
                    return true;

                case IDC_RADIO3:
                    curRadioOption = 3;
                    return true;
            }
    }

    return FALSE;
}


int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    hInst = hInstance;

    // The user interface is a modal dialog box
    return DialogBox(hInstance, MAKEINTRESOURCE(DLG_MAIN), NULL, (DLGPROC)DialogProc);
}

Re: Sending message between objects

aangerma16-Feb-12 19:57

aangerma

16-Feb-12 19:57

Thanks for your replay , I didnt understand where is the calling to the method of object 2,

if you can mark this section it will be helpfull for me.

by the way I forgot to specify that I am using MFC but as I realized it doesnt matter.

thanks

Re: Sending message between objects

enhzflep16-Feb-12 22:35

enhzflep

16-Feb-12 22:35

That's okay. In fact - I didn't make any call to the method of object 2. Please accept my apology for being unclear.

As I alluded to earlier, I can see two places where such a call would make sense.
In the first case, there would be action immediately after a radio button was pressed.
I imagine you would not have the same need to keep track of the currently selected option, so I've omitted that code from the following case statements.

Example 1: Immediate response

C++

case IDC_RADIO1:
    object2.handleSelectedRadioButton(1);
    return true;

case IDC_RADIO2:
    object2.handleSelectedRadioButton(2);
    return true;

case IDC_RADIO3:
    object2.handleSelectedRadioButton(3);
    return true;

In this second example, you'll need to remember which radio-button is selected somewhere, before taking the appropriate action when the trigger is received (in this case, the pressing of the button labelled Test)
Example 2: Action taken in response to another input

C++

case IDC_BTN_TEST:
              if (curRadioOption == -1)
                  MessageBox(hwndDlg, "Select a radio button first!", "Error", MB_ICONERROR);
              else
                   object2.handleSelectedRadioButton(curRadioOption);
              return TRUE;

Something else I should mention, is that MFC will most likely allow the state of any control to be quickly and easily queried (not sure if there's an object used to represent a group of radio buttons - I'd imagine that there was) This will make my global variable curRadioOption redundant.

Re: Sending message between objects

JackDingler17-Feb-12 10:35

JackDingler

17-Feb-12 10:35

Pass a pointer to the object you want to notify in the constructor of the dialog, and have the dialog save that in a member variable.

Then when events occur, make a call to that object.

Control Multiple Dialog boxes in SDI application

johnjitu16-Feb-12 4:35

johnjitu

16-Feb-12 4:35

Hello
Thanks in advance.I have created different dialog for which are link by the main menu,but my problem is if i go from one dialog to another , how can i close it and save its contents

Waiting for reply soon

Re: Control Multiple Dialog boxes in SDI application

David Crow16-Feb-12 4:39

David Crow

16-Feb-12 4:39

johnjitu wrote:
...if i go from one dialog to another , how can i close it and save its contents

The dialog is closed by clicking the Cancel button, the X, Esc, Alt+F4, or by calling EndDialog(). Where are you wanting to save its data to? Some internal data structure, or some external storage like a file?

Re: Control Multiple Dialog boxes in SDI application

johnjitu16-Feb-12 5:03

johnjitu

16-Feb-12 5:03

Thanks

I did not put any cancel or close,it is without title bar.I make sdi application with
full screen and in menu of upper level i put the chose where you can open the new
dialog.I am calling dialog boxes from the Viewclass.but didnot find how to close or switch to other dialog when user click the other options of open other dialogs

Do yo have any coding to calling mulitple dialogboxes in SDI applicaiton

Thanks

Re: Control Multiple Dialog boxes in SDI application

David Crow16-Feb-12 5:06

David Crow

16-Feb-12 5:06

johnjitu wrote:
Do yo have any coding to calling mulitple dialogboxes in SDI applicaiton

You need to first understand the difference between modal and modeless dialogs.

how to add image in SDI

sarfaraznawaz16-Feb-12 2:52

sarfaraznawaz

16-Feb-12 2:52

hi
i looking to load the image in an window how can i do it i tried with CpictureHolder .does any alternative way to do it.
note am not looking to load on background
Reply as soon as possible .

thanks sarfaraz
Poke tongue | ;-P

Re: how to add image in SDI

Richard MacCutchan16-Feb-12 4:19

Richard MacCutchan

16-Feb-12 4:19

Perhaps CImage[^] is what you need.

Unrequited desire is character building. OriginalGriff
I'm sitting here giving you a standing ovation - Len Goodman

How to create OLE object for MS Office

LionAM15-Feb-12 23:31

LionAM

15-Feb-12 23:31

Hello,
is there any c++ tutorial or (simple) open source sample how to write an OLE object that can be embedded into MS Office applications such as powerpoint?
Just like, for example, an Origin Graph or a corel draw image which are directly embedded into a powerpoint presentation.

When I search for OLE, I most often only find how to automate Office...

Alex

Re: How to create OLE object for MS Office

CPallini16-Feb-12 0:36

CPallini

16-Feb-12 0:36

If you are using Visual Studio, then the simplest path is the MFC ActiveX Control Wizard[^].

Veni, vidi, vici.

Re: How to create OLE object for MS Office

LionAM16-Feb-12 4:51

LionAM

16-Feb-12 4:51

Thank you - this was easier than I expected.

Alex

Re: How to create OLE object for MS Office

LionAM16-Feb-12 5:59

LionAM

16-Feb-12 5:59

I can insert my ActiveX object into Powerpoint and save/restore the data.

Now, I would like to automatically create a new object from a certain file type - ideally by drag and drop into Powerpoint. How can I achieve this?

Thank you in advance.

Alex

Re: How to create OLE object for MS Office

CPallini16-Feb-12 9:23

CPallini

16-Feb-12 9:23

I never did that, however, I suppose you have to write a Shell Extension for that, check out the great article series[^] of Michael Dunn, here at CodeProject.

Veni, vidi, vici.

Re: How to create OLE object for MS Office

LionAM16-Feb-12 21:04

LionAM

16-Feb-12 21:04

I have found an example which works as expected:

http://msdn.microsoft.com/en-us/library/8c47csfz%28v=vs.90%29.aspx[^]

Alex

MFC Multiple Splitter for MDI Application

SHWRRMSH15-Feb-12 23:29

SHWRRMSH

15-Feb-12 23:29

I read this article on creating multiple splitter views on a Window using an MFC SDI Application.
http://www.vckbase.com/english/code/doc_view/SdiMulti.shtml.htm[^]

How can I choose the split (For eg:- 1x2, 3x1 etc.,) from the menu bar and split the *current window* (not a new window) for an MDI Application?

Re: MFC Multiple Splitter for MDI Application

Jochen Arndt16-Feb-12 0:11

Jochen Arndt

16-Feb-12 0:11

Please don't post the same question at multiple places.
The identical question in the Q&A section [^] already contains answers.

Re: MFC Multiple Splitter for MDI Application

SHWRRMSH16-Feb-12 0:16

SHWRRMSH

16-Feb-12 0:16

Alright, Fine, I got that. Now any answers?

call C# function from C++ dll

Paulraj G15-Feb-12 20:15

Paulraj G

15-Feb-12 20:15

Hi All,

I have a function in C++ dll like

C++

FunctionCPP(int s)
{
}

I have a function in C# application(exe) like

int FunctionCSharp(int s)
{
     return s;
}

what is the procedure to call FunctionCSharp from FunctionCPP?

Any help will be appriciated.

Thanks

G.Paulraj

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